#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include <stdlib.h>

int main() {
    int a, b, c;
    while (scanf("%d %d %d", &a, &b, &c) != EOF)
    {
        if ((a + b > c) && (abs(a - b) < c))
        {
            if (a == b && b == c)
                printf("Equilateral triangle!\n");
            else if (a == b || a == c || c == b)
                printf("Isosceles triangle!\n");
            else
                printf("Ordinary triangle!\n");
        }
        else {
            printf("Not a triangle!\n");
        }
    }
    return 0;
}